ES2317551T3 - CONVEYOR AND PROCEDURE FOR DEVIATION OF VERY TOGETHER ITEMS. - Google Patents

Abstract

A conveyor and associated method for diverting closely spaced articles conveyed along the conveyor. The conveyor includes a conveyor belt with belt rollers oriented to rotate on axes oblique to the direction of belt travel. A series of arrays of bearing surface elements are arranged end to end along the length of the conveyor. The bearing surfaces may be static or rotational. Each array defines a roller-control zone in which the array is selectively activated with its bearing surface elements in contract with the belt rollers or deactivated with its bearing surface elements out of contact with the belt rollers. As the belt advances through an activated roller-control zone, the belt rollers rotate to propel a conveyed article toward a side of the belt. The contiguous roller-control zones are sequentially activated and deactivated to direct articles to the side and off the belt or to let them pass straight through. The length of the entire series of roller-control zones determines the lateral extent of the sidewise diversion. The length of each roller-control zone determines the minimum gap between consecutively conveyed articles. The serial cascade of these roller-control zones permits the tight sortation of closely spaced articles for high throughput.

Description

Conveyor and diversion procedure of articles very close together.

Background

The invention refers globally to mechanically driven conveyors and, more particularly, to conveyors provided with conveyor belts with rollers support for items that rotate on oblique axes to the direction of band displacement when coupled by surfaces of support sequentially activated to come into contact with rollers in contiguous areas along the conveyor.

Modular plastic conveyor belts with article support rollers that extend beyond the outer and inner surfaces of the band are used in Many conveyor applications. When the rollers are arranged to rotate in oblique axes in the direction of band displacement and are connected by surfaces of support on the inner surface of the band, the rollers can boost items transported to the side of the belt to As it progresses. Support surfaces in an area of the conveyor can be raised in an activated position in contact with the rollers from a lower position, deactivated out of contact with the rollers. Support surfaces conventionally they are flat wear surfaces or surfaces cylindrical outer rollers that are free to rotate in axes in the direction of band movement. Sometimes consecutive transported items are required to be addressed to different locations. For example, a head article can have to be diverted off the side of the band to another transporter while a queue item may have to continue  without being diverted along the conveyor. If the surfaces of support activate the rollers when the head article is mounted on top of them, the article will be directed off the side of the band, after which the support surfaces are descended to deactivate the rollers to allow the tail item run with the band without being diverted. The length of the section of the raised and lowered support surface defines the minimum separation between consecutive items since two items should not be on the band in a zone activated at Same time.

This transport scheme is effective in many applications, such as the classification of articles. But the displacement of an article across the width of a broadband requires an activated zone of extended length and, by consequently, greater separation between transported items consecutive. The increase in separation reduces the yield of the conveyor US 2001/0045346 discloses a band conveyor with cylindrical rollers that can rotate around of oblique axes to the direction of band movement and which can be rotatably operated from below using the coupling of the lower surfaces of the rollers with roller bearing surfaces, optionally mobile inside and out of contact with the rollers, which extend and run in the direction of band movement.

Therefore, there is a need for a conveyor that can quickly divert items very close together for classification and other transport applications.

Summary

This need and other needs are met through a conveyor that incorporates the characteristics of the invention. In one aspect of the invention, a conveyor comprises a stretch of transport that extends from one extreme waters up to one end downstream. A conveyor belt is held in the transport section and moving in a direction of displacement of the band from the upstream end to the downstream end of the transport section. Conveyor belt extends laterally from a first lateral edge to a second lateral edge and in thickness from an outer surface to an inner surface. Conveyor belt additionally includes belt rollers with protruding parts that extend beyond the outer and inner surfaces of the conveyor belt The band rollers are arranged to rotate in oblique axes to the direction of travel of the band. A series of supporting surface elements are arranged end to end in the direction of travel of the band along the transport section. The elements of Support surface are individually mobile inside and outside the contact with the protruding parts of the belt rollers that are extend beyond the inner side of the conveyor belt.

In another aspect of the invention, a system of conveyor comprises a conveyor that extends from a upstream end to a downstream end and laterally from a first side to a second side. A band conveyor held on the conveyor moves in one direction of displacement of the band from the upstream end to the downstream end of the conveyor. The band has rollers of the band arranged to rotate in oblique axes to the direction of band displacement. The band rollers extend to through a transport side of the band on top of which the Items are transported and from an opposite side. A series of contiguous roller control zones are formed of end to end along the conveyor in the direction of the band displacement. Each roller control zone includes at least one support surface arranged on the side opposite of the conveyor belt. A drive coupled to the support surface displaces the support surfaces to a first position and to a second position. In the first position, the Support surface is in contact with the belt rollers in the zone of control of the rollers to activate the zone of control of the rollers causing the band rollers to rotate as the band advances. The rotation of the band rollers diverts items transported in the activated control zone of the rollers to the first side of the conveyor. In the second position, the support surface is out of contact with the belt rollers in the roller control zone for deactivate the control zones of the rollers, which allows that the items continue to be transported at the address of the band displacement.

Another aspect of the invention provides a procedure for use with a conveyor comprising  a conveyor belt that advances in a direction of displacement of the band and which is provided with a plurality of belt rollers that are arranged to rotate on shafts oblique to the direction of band movement and that extend beyond the conveyor surface of the belt to hold items transported and beyond a surface opposite of the belt in rolling contact with the surfaces of support for. The procedure, which serves to selectively divert very close articles transported on the band, includes: (1) the arrangement of the support surfaces in individual groups arranged end to end in the direction of travel of the belt to define associated roller control zones arranged contiguously along the conveyor; and (2) activate selectively each roller control zone displacing the associated group of bearing surfaces in contact with the rollers of the belt in the conveyor belt and deactivating selectively each roller control zone displacing the associated group of support surfaces out of contact with belt rollers on the conveyor belt.

In yet another aspect of the invention for the use with a similar conveyor, a procedure for diversion of items transported on the belt includes: (1) the formation of a series of contiguous areas of control of rollers along the conveyor in the direction of band displacement, in which each control zone of the rollers have at least one support surface selectively mobile between a first position in contact with the rollers of the belt in the control zone of the rollers to activate the zone of roller control and a second position out of contact with the belt rollers in the roller control zone to deactivate the roller control zone; (2) the activation of a first roller control zone when a transported item enters the first control zone of the rollers; (3) the activation of a second contiguous control zone of the rollers when the transported article enters the second control zone of the rollers from the first control zone of the rollers; and (4) deactivation of the first control zone of the rollers after the transported article leaves the first roller control zone.

Brief description of the drawings

These characteristics and these aspects of the invention, as well as its advantages, will be better understood with reference to the following description, the claims attached and the attached drawings, in which:

Figures 1A and 1B are plan diagrams from above and in side elevation of a conveyor that incorporates the features of the invention;

Figure 2 is an isometric view of a part of a conveyor like that of figures 1A and 1B, showing a single roller control zone;

Figure 3 is a front elevation view of a part of another version of the conveyor like the one in the figures 1A and 1B incorporating a band support surface of wear;

Figure 4 is a top view of the conveyor of figure 3,

Figures 5A and 5B to Figures 9A and 9B they are diagrams in plan from above and in lateral elevation that show the operation of a conveyor like that of Figures 1A and 1B step by step;

Figure 10 is a plan diagram from above another version of a conveyor that incorporates the characteristics of the invention including control zones of the seated brick rollers;

Figure 11 is a plan diagram from above yet another version of a conveyor that incorporates the features of the invention including control zones of the zigzag rollers; Y

Figure 12 is a diagram in side elevation of yet another version of a conveyor that incorporates features of the invention that includes control zones of the rollers that advance with the conveyor belt.

Detailed description

A version of a conveyor that incorporates The features of the invention are illustrated in Figures 1A and 1 B. The conveyor 10 provides a transport surface in form of a modular conveyor belt 12 driven in a direction of travel of the band 14 by a set of 16 drive sprockets mounted on a motor driven shaft 17. The band, which extends laterally across the width from a first lateral edge 18 to a second lateral edge 19, is oriented around the set of driving sprockets in a downstream end 20 of transport section 22 and a set of crazy cogwheels (not shown) at an upstream end of the transport section. The band, which is an endless loop, return from the downstream end to the upstream end to along a return segment (not shown) below the transport section.

The band is characterized by a plurality of belt rollers 24 and rotate on axes 26 oblique to the direction of the displacement of the band 14. Outgoing parts 28 of the belt rollers protrude beyond surfaces outer and inner 30, 31 of the band. The underlying 32 rollers to the part of the transport section of the band are high selectively 34 to contact and descended 35 out of contact with the protruding parts of the band rollers that are extend beyond the inner surface of the band. Every roller 32 is a longitudinal roller that can rotate freely on an axis 36 in the direction of movement of the band. The rollers are arranged in longitudinal roller dies laterally separated in longitudinal rails that extend below the band rollers. Each roller die Longitudinal defines a control zone of rollers 38 at length of conveyor length Drives, such as pneumatic, hydraulic or electric drives raise and descend each matrix. When a matrix is raised as, by example, the two roller matrices of further downstream in the Figure 1B, rolling friction between rollers in contact with the belt rollers causes Both turn. The oblique orientation of the band rollers causes the items 40 on top of the belt rollers in an activated zone are forced forward and laterally as indicated by arrow 42. Articles 40 in an area deactivated or in a part of the transport section of the conveyor  without any longitudinal rollers move in the direction of the band displacement because the band rollers do not They are forced to turn. To improve the friction coupling of the rollers of the belt by the longitudinal rollers, the Band rollers preferably have a rubber jacket or of elastomer around its peripheries and rollers Longitudinally they are coated with urethane.

The conveyor system in the example of Figures 1A and 1B are represented with two conveyors of extraction 44, 45 that extend obliquely from the first side edge of main conveyor 10, such as in a classification application. The longitudinal roller dies they are represented in groups of three matrices arranged end to end just upstream and along the mouth of each  extraction conveyor Each matrix is activated or deactivated independently and selectively to divert or pass a item transported when transported through the area associated. The length of each matrix or control zone of the rollers in the direction of belt travel determines the minimum length of space G that separates transported items consecutive. In general, roller control zones more Short means more items together. But to divert an article which is mounted along the left side of the band conveyor outside the right side requires a certain length of activated rollers. Download in cascade a series of matrices of sequentially activated longitudinal rollers from end to end provides the necessary extended contact distance to divert an item out or to the side of the band while It allows a close separation of consecutive articles.

A simple roller control zone is depicted in figure 2. Belt 12 is a conveyor belt of modular plastic consisting of individual rows 48 of one or more 49 band modules connected together from one end to another by means of articulation rods in articulation joints 50. Cavities 52 in the belt admit rollers of the rotating band 24 on oblique axes to the direction of travel of the band 14. A modular plastic band provided with these characteristics is Angled Roller? 400 series band manufactured and sold by Intralox, L.L.C. from Harahan, Louisiana, U.S.A. The modules of the Band are made of a thermoplastic polymer, such as by example polypropylene, polyethylene, acetal and composites, by injection molding. The longitudinal rollers 32 are arranged side by side with each roller that can rotate around a longitudinal axis 54 in the direction of band displacement. Each longitudinal roller extends below a longitudinal rail 56 of the belt rollers.  The belt is held along the transport section on narrow rails 58 between adjacent longitudinal rails of rollers The longitudinal rollers are mounted on a frame common (not shown) that includes roller bearings in Each end of the rollers. The frame is activated to lift and lower all longitudinal rollers together in and out of contact with the band rollers. When the area of Roller control is activated with the roller matrix in a elevated position, the band rollers act in conjunction with longitudinal rollers in rolling contact, with little or no slippage, as the band advances in the direction of band displacement. The coupling between the rollers is improvement by cylindrical urethane support surfaces 60 of the longitudinal rollers and the rubber sleeve or of elastomer 62 around the periphery of the rollers of the band.

Another version of the support surface is depicted in figures 3 and 4. Instead of on the rollers, the bearing surface 64 is formed on wear bands 66 which extend in the direction of the movement of the band 14 under longitudinal rails of belt rollers. The bands of wear are held on top of 68 air chambers mounted on a bed of the transport section 70. The band itself is supported on rails 58 placed between the longitudinal rails of the band rollers. The air chambers, which act as drives for the support surfaces are driven pneumatically by a control valve 72 that is supplied with compressed air by a compressor 74. The valve is controlled by a control 76, such as a logical control programmable or another smart device. The air is injected inside the air chambers to raise the wear bands and is released to descend as indicated by arrow 78. In an elevated position, the surface of flat support 64 of the wear bands is in contact with the protruding part of the rollers 24 extending beyond the inner surface 31 of the band. This contact causes the band rollers rotate. The protruding part of the rollers of the oblique band protruding beyond the outer surface 30 of the band propel the items transported 40 to the side from the band. In a lowered position, wear bands 66 'descends rest on top of a deflated air chamber 68 'out of contact with the band rollers.

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As also shown in Figure 4, the belt rollers 24 rotate on axes 26 oblique to the direction of belt displacement 14. Drills through rollers admit a shaft 80 held at its ends inside the band module. The axis, of course, defines the axis of rotation of the roller and causes the belt roller to contact a underlying support surface 64 rotate in the direction of the arrow 82 as the band progresses. The angle? Of the roller is the angle between its axis of rotation and a lateral axis 84 perpendicular to the direction of band movement. Roller angles of approximately 30º or less work well with a band of flat wear For larger angles, such as 45º and 60º, it require longitudinal rollers as surface elements of support to reduce slippage and the consequent friction of sliding between the belt roller and the surface of support for.

The operation of the conveyor is represents step by step in figures 5A and 5B up to figures 9A and 9B. A head article 40 is shown above the conveyor in figures 5A and 5B. All the elements of the bearing surfaces 86, whether rollers or wear bands, in all roller control zones are deactivated (indicated as a descended position). This allows the Article 40 above the belt rollers that do not rotate 24 feed along the conveyor in the direction of the band offset with band 12. Sensors 88, such as optical sensors or proximity switches, can be used to detect the entry or exit of an item transported from a roller control zone 38. Sensor signals that indicate the location of the items transported along of the roller control zones are sent to the control to Control the zones.

In Figures 6A and 6B, a glue article 40 ' follow the head article 40 in a part upstream of the section Conveyor transport. Since the head article goes to be classified outside the conveyor side until the downstream extraction conveyor 45, the first zone of 38A downstream roller control is activated as soon as The head article enters. With oblique band rollers in rolling contact with the raised bearing surface in the zone, the head article is directed towards the side of the band. Meanwhile, the roller control zones below the queue article are deactivated (descended) and article of tail is still mounted with the band.

When the head article makes its turn towards the downstream extraction conveyor in figures 7A and 7B, enters the second control zone of the downstream rollers 38B, which is activated then. The head article, which is placed on both sides of both activated zones, it is propelled towards The extraction conveyor. Meanwhile, the tail article continues mounted with the band through the control zones deactivated

As soon as the head article 40 leaves the first downstream control zone 38A, the elements of the support surface are descended to deactivate the area in anticipation of the arrival of the tail article 40 ', as depicted in figures 8A and 8B. Meanwhile, the third zone of 38C downstream roller control is activated to continue pushing, together with the roller control zone 38B, the head article towards the side edge of the band on the downstream extraction conveyor 45.

As depicted in Figures 9A and 9B, a Once the head article 40 is cleared, the control zones of the second 38B and third 38C rollers are deactivated individually (descended). This allows the queue article 40 'pass through the roller control zones without being diverted out of the conveyor belt.

In the versions described so far, the supporting surface elements that define control zones of the consecutive rollers were separated by lines of straight demarcation across the width of the conveyor belt. In the conveyor shown in Figure 10, elements of consecutive support surface 88, 88 ', each of them composed of a matrix of longitudinal rollers, are arranged in a laterally superimposed masonry model to eliminate the linear deadband that extends laterally through the Conveyor between consecutive zones. This version has a line 90 square wave demarcation between zones Consecutive roller control. Another version is represented in figure 11, in which consecutive matrices 92, 92 ', 92' ' they are forming zigzag along demarcation lines diagonally staggered 94, 94 '. The ends upstream of the bearing surfaces along the second side edge 19 are placed upstream of the ends upstream of the bearing surfaces along the first side edge 18 for divert items to the first side edge. This provision in  zigzag provides items closer to the second edge lateral a diagonal path extended through the zones activated enough to move the items across the width Complete of the conveyor belt.

Figure 2 shows a conveyor in the which a control zone of the rollers 96 moves with the conveyor belt 12. In this example, the support surfaces of a matrix of longitudinal rollers 97 define each zone of Roller control that moves. A series of matrices of end to end establishes contiguous areas of control of moving rollers that can be activated or deactivated selectively in or out of contact with the rollers of the band. Alternatively, a single matrix that moves quickly It can be used in applications where articles do not require extremely close separation. A joint multi-bar 98 connected to each roller array and that rotates around an articulation axis 99 advances the die to the speed of the band or the speed of the article in the direction of the band offset and returns the matrix along a return path to place it for another item. Moving with a transported item, the control zone of The rollers can be shorter and the items can be even closer than the length of the rollers in the band.

Therefore, the conveyor belt with oblique rollers sequentially activated in control zones of the cascading rollers end to end in the mouth of each lateral extraction conveyor is ideal for classification High-performance items very close together and for any other application that requires that items close together be displaced laterally as the band advances.

Although the invention has been described in detail with reference to a few preferred versions, they are possible Other versions. For example, drives do not have to be pneumatically operated air chambers, but they can be hydraulically or electrically operated mechanisms. As another For example, fewer sensors than those shown in Figure 5B. Setting the activation time of each zone of Roller control based on empirical data, the band speed and bandwidth or using tree signal encoders or other techniques of band speed detection, only a single one is necessary sensor to detect the entry of an item in the control zone of the upstream rollers in a series of areas of end to end Still as another example, activation and sequential deactivation in synchronism with the advance of a item transported to be diverted can be done in a way different from the elevation and descent of an array of elements of support surface, which can be alternately inclined or laterally moved inside out of contact with the rollers from the band. Although the preferred belt is a conveyor belt of modular plastic, other modular bands can be used that They are not plastic or even flat bands with oblique rollers. Y the rollers may not require rubber sleeves, especially if The angle of the roller is not too large. In addition, the conveyor may consist of two roller bands oblique side by side in which each has rollers ready to direct items transported sideways opposite sides of the conveyor. Alternatively, a single band with longitudinal rails that alternate with rollers of the band oriented in different directions and support surfaces Associates can be used to classify items outside of opposite sides of the band. Drives can switch the supporting surface elements between the alternating rails to selectively divert items off each side of the band. Therefore, as these few examples suggest, the scope of the claims does not mean that it is limited to Preferred versions described in detail.

Claims (26)

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1. A conveyor comprising a conveyor transport section (22) extending from an upstream end to a downstream end (20) with a conveyor belt (12) held in the transport section to advance in a direction of travel of the belt from the upstream end to the downstream end, in which the conveyor belt extends laterally from a first lateral edge (18) to a second lateral edge (19) and in thickness from an outer side (30) to an inner side (31) and additionally includes belt rollers (24) provided with protruding parts (28) extending beyond the outer and inner sides of the conveyor belt and arranged to rotate in axes (26) oblique to the direction of band movement on supporting surface elements; characterized by a series of supporting surface elements (32; 64; 86; 88; 93; 97) disposed end to end in the direction of the band movement along the transport section individually movable in and out of the contact with the protruding parts of the belt rollers extending beyond the inner side of the conveyor belt. 2. A conveyor according to claim 1 in which the supporting surface elements comprise rollers cylindrical that can rotate in shafts (36) parallel to the direction of the displacement of the band. 3. A conveyor according to claim 1 in which each supporting surface element comprises a group of laterally displaced support surfaces that extend into the direction of band movement from a first end to a second end and in which each group of elements of Support surface is mobile as a group inside and outside the contact with the band rollers. 4. A conveyor according to claim 1 in which each supporting surface element comprises a group of Zigzag bearing surfaces (92) in the direction of the band offset and in which each group of elements of Support surface is mobile as a group inside and outside the contact with the band rollers. 5. A conveyor according to claim 1 in which parts of consecutive support surface elements (88; 92) overlap each other laterally. 6. A conveyor according to claim 1 in which each supporting surface element advances in the direction of the displacement of the band. 7. A conveyor according to claim 1 in which each supporting surface element extends in the direction of band travel up to a length generally equal to the minimum separation between items consecutive transported on the upstream end of the section Of transport. 8. A conveyor according to claim 1 in the one that all the rollers of the band turn in parallel axes or collinear. 9. A conveyor according to claim 1 in the one that the series of supporting surface elements arranged of end to end in the direction of band movement a along the transport section define contiguous control zones of the rollers (38; 96) in the conveyor belt and in which the transporter additionally comprises sensors (88) that detect the entry of an item transported inside the area of roller control. 10. A conveyor according to claim 1 additionally comprising a drive (68; 98) coupled to each support surface element to selectively displace the support surface element in and out of contact with the protruding parts of the band rollers that extend beyond the inner side of the conveyor belt. 11. A conveyor according to claim 1 additionally comprising drives coupled to the series of support surface elements actuated to displace sequentially the supporting surface elements inside and outside of contact with the protruding parts of the belt rollers that extend beyond the inner side of the band conveyor in synchronism with the advance along the stretch of conveyor transport of a transported item that is going to divert. 12. A conveyor system comprising a conveyor (10) extending from an upstream end (20) and laterally from a first side (18) to a second side (19) and a conveyor belt (12) held on the conveyor for advancing in a direction of movement of the belt (14) from the upstream end to the downstream end of the conveyor, the conveyor belt including belt rollers (24) arranged to rotate in axes (26) oblique to the direction of the movement of the belt and extending through the conveyor belt from a transport side (30) on which items are transported to the opposite side (31) characterized by a series of contiguous roller control zones ( 38; 96) formed end-to-end along the conveyor in the direction of belt travel, each roller control zone including: - at least one support surface (32; 64; 86; 88; 93; 97) arranged on the opposite side of the band conveyor

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- a drive (68; 98) coupled to the minus a support surface to move the support surface to a first position in contact with the belt rollers in the roller control zone to activate the control zone of the rollers to divert articles to the first side of the conveyor causing belt rollers to rotate as that the band advances and a second position out of contact with the belt rollers in the roller control zone for deactivate the roller control zone to allow the items continue to be transported at the address of the band displacement. 13. A conveyor system according to the claim 12 further comprising sensors (88) for detect the items that are being transported through the control zones of the rollers. 14. A conveyor system according to the claim 12 wherein the at least one bearing surface it comprises a plurality of cylindrical rollers that can rotate in axes parallel to the direction of band movement. 15. A conveyor system according to the claim 12 wherein each roller control zone is extends in the direction of band movement up to a length generally equal to the minimum separation between items Consecutive transported on the conveyor. 16. A conveyor system according to the claim 12 wherein all the band rollers rotate in parallel or collinear axes. 17. A conveyor system according to the claim 12 wherein each roller control zone It has diagonal ends upstream and downstream. 18. A conveyor system according to the claim 12 wherein roller control zones consecutive overlap sideways. 19. A conveyor system according to the claim 12 wherein the roller control zones move in the direction of band movement. 20. A conveyor system according to the claim 12 further comprising a path for receive the diverted items (44; 45) arranged on the first side of the transporter to receive items diverted outside the conveyor by selective activation of the areas of roller control. 21. For use with a conveyor (10) comprising a conveyor belt (12) that advances in the direction of band travel (14) and provided with a plurality of belt rollers (24) that are arranged to rotate in shafts (26) oblique to the direction of travel of the band and that extend beyond the transport surface (30) of the band to hold items transported and beyond of an opposite surface (31) of the band within the contact of rolling with bearing surfaces (32; 64; 86; 88; 93; 97), a procedure to selectively divert articles closely together transported on the belt comprising: - the arrangement of support surfaces in individual groups arranged end to end in the direction of band offset to define associated zones of control of the rollers (38; 96) arranged adjacent to conveyor length; - selectively activate each zone of roller control by displacing the associated group of surfaces  of support within the contact with the rollers the band in the band conveyor and selectively deactivate each zone of roller control by displacing the associated group of surfaces of support outside the contact with the rollers of the band in the conveyor belt. 22. The method according to claim 21 additionally comprising the detection of an article transported in or out of a control zone of rollers 23. The method according to claim 21 additionally comprising the sequential activation of zones contiguous roller control to direct an article transported laterally through the conveyor belt. 24. The method according to claim 21 additionally comprising the separation of consecutive articles  transported on the conveyor belt through a space by at least as large as the extent of each control zone of the rollers in the direction of the band movement. 25. For use with a conveyor (10) comprising a conveyor belt (12) that advances in the direction of band travel (14) and provided with a plurality of belt rollers (24) that are arranged to rotate in shafts (26) oblique to the direction of travel of the band and that extend beyond the transport surface (30) of the band to hold items transported and beyond of an opposite surface (31) of the band within the contact of rolling with bearing surfaces (32; 64; 86; 88; 93; 97), a procedure for selectively diverting transported items about the band comprising: - the formation of a series of contiguous areas of control of the rollers (38; 96) along the conveyor in the direction of band movement, each control zone of the rollers being provided with at least one surface of selectively mobile support between a first contact position with the belt rollers in the roller control zone to activate the roller control zone and a second position out of contact with the belt rollers in the area of roller control to deactivate the control zone of the rollers; - the activation of a first control zone of the rollers (38A) when the transported article enters the first roller control zone; - the activation of a second contiguous zone of roller control (38B) when the transported item enters in the second roller control zone from the first zone roller control; - deactivation of the first control zone of the rollers after the transported article leaves the first roller control zone. 26. The method according to claim 25 additionally comprising the activation of a third zone of roller control (38C) adjacent to the second control zone of the rollers when the transported article enters the third control zone of the rollers from the second control zone of the rollers